Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of the first image in a sequence for a display screen or portion thereof with transitional graphical user interface, showing our new design;

FIG. 2 is a front view of the second image thereof;

FIG. 3 is a front view of the third image thereof;

FIG. 4 is a front view of the fourth image thereof;

FIG. 5 is a front view of the fifth image thereof;

FIG. 6 is an enlarged view of the claimed portion thereof in FIG. 1;

FIG. 7 is an enlarged view of the claimed portion thereof in FIG. 2;

FIG. 8 is an enlarged view of the claimed portion thereof in FIG. 3;

FIG. 9 is an enlarged view of the claimed portion thereof in FIG. 4; and,

FIG. 10 is an enlarged view of the claimed portion thereof in FIG. 5.

The outer perimeter illustrated by a pair of dashed broken lines represents a display screen or portion thereof and forms no part of the claimed design. All other dashed broken lines illustrate portions of the graphical user interface and form no part of the claimed design.

The appearance of the transitional graphical user interface sequentially transitions between the images shown in FIGS. 1-5 and FIGS. 6-10. The process or period in which one image transitions to another forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with transitional graphical user interface, as shown and described. 